1. Field of the Invention
The present invention relates to a battery pack air cooling structure provided with a thermoelectric element, and more particularly, to a battery pack air cooling structure provided with a thermoelectric element installed at an inlet of a cooling passageway controlling the temperature of each cell module assembly.
2. Description of the Related Art
Environmentally-friendly vehicles such as electric vehicles or fuel cell vehicles in which no exhaust gas is discharged and batteries are mounted on the environmentally-friendly vehicles to drive motors of the vehicles.
In electric vehicles the reliability and stability of a battery system are important factors for determining marketability of electric vehicles and an appropriate temperature range of the battery system must be maintained at about 35° C. to 40° C. to prevent the performance of a battery from deteriorating due to a change of various external temperatures. Therefore, a thermal control system for a pouch cell module that has excellent heat dissipation performance in a general climate condition (e.g., an appropriate temperature range for a battery system) and is capable of maintaining an appropriate temperature of the battery in a low temperature environment is required.
Generally, a battery pack assembly (BPA) is heated when a vehicle is driven or charged. An air cooling method is usually used as a method of cooling the BPA including a plurality of cell module assemblies. In particular, in a hybrid vehicle, cooling is performed by air supplied from a cabin of the vehicle and air supplied from a heating, ventilation, air conditioning (HVAC) system. In particular, a structure in which the BPA is cooled by one blower at one temperature has been generally used and the technology for minimizing a temperature difference according to a cell module assembly (CMA) has not been used due to the difficulty in forming a flow passageway. In addition, air conditioning may be performed to cool the BPA; however, then, an additional cooling device is required, or a vehicle air conditioner must operate at a reduced efficiency.
Furthermore, when the BPA is charged or discharged, a voltage difference occurs based on a temperature difference. The temperature difference operates as a variable in lowering the performance of the BPA. In other words, when one cell module assembly in which a substantial temperature difference occurs, may be damaged by deterioration and a damaged battery operates as a resistor and generates a high temperature. Deterioration may also occur in adjacent cell module assemblies, which may cause damage to the entire battery. When a substantial voltage difference occurs in each cell module assembly, an undesired result may occur in each driving motor unit of an electric vehicle in which a uniform voltage is an optimum usage condition.